U.S. patent number 7,607,942 [Application Number 12/191,922] was granted by the patent office on 2009-10-27 for multi-shot coaxial connector and method of manufacture.
This patent grant is currently assigned to Andrew LLC. Invention is credited to Kendrick Van Swearingen.
United States Patent |
7,607,942 |
Van Swearingen |
October 27, 2009 |
Multi-shot coaxial connector and method of manufacture
Abstract
A coaxial cable connector formed via multi-shot injection
molding has a body formed by multiple injection molding layers of
different injection moldable materials about a central inner
contact to form an integral connector body. The connector body is
provided with a coaxial dielectric spacer of dielectric polymer
surrounding the inner contact; a coaxial inner body of injectable
molded metal composition surrounding an outer diameter of the
dielectric spacer; and an outer body of polymer surrounding the
inner body. A range of different coupling bodies compatible with
the connector body may also be formed via injection molding to
provide connectors compatible with a range of different coaxial
cable configurations.
Inventors: |
Van Swearingen; Kendrick
(Woodridge, IL) |
Assignee: |
Andrew LLC (Hickory,
NC)
|
Family
ID: |
41161319 |
Appl.
No.: |
12/191,922 |
Filed: |
August 14, 2008 |
Current U.S.
Class: |
439/578; 29/828;
29/856 |
Current CPC
Class: |
B29C
45/16 (20130101); H01R 9/0521 (20130101); H01R
13/504 (20130101); H01R 43/18 (20130101); H01R
43/24 (20130101); B29C 45/14639 (20130101); B29C
2045/1696 (20130101); H01R 13/5205 (20130101); Y10T
29/49123 (20150115); H01R 13/622 (20130101); H01R
24/40 (20130101); H01R 2103/00 (20130101); Y10T
29/49172 (20150115); H01R 13/5219 (20130101) |
Current International
Class: |
H01R
9/05 (20060101) |
Field of
Search: |
;439/578
;29/828,858,860,856,883 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gushi; Ross N
Attorney, Agent or Firm: Babcock IP, PLLC
Claims
I claim:
1. A coaxial cable connector, comprising: a connector body
multi-shot injection molded about an inner contact; the connector
body comprising: a dielectric insulator of dielectric polymer
molded upon an outer diameter of the inner contact; a coaxial inner
body of injectable molded metal composition molded upon an outer
diameter of the dielectric spacer; and an outer body of polymer
injection molded upon an outer diameter of the inner body.
2. The coaxial cable connector of claim 1, further including: a
polymeric coupling body threadably coupled to the outer body.
3. The coaxial cable connector of claim 1, further including: an
annular ramp surface formed on an end face of the inner body, a
generally cylindrical slip ring positioned within a bore of the
connector body, a clamp spring positioned between the annular ramp
surface and the slip ring, and a polymeric coupling body threadably
coupled to the outer body operative to drive the slip ring against
the clamp spring.
4. The coaxial connector of claim 1, further including: an annular
ramp surface formed on an end face of the inner body, a clamp
spring positioned between the annular ramp surface: and a polymeric
coupling body threadably coupled to the outer body operative to
drive the clamp spring towards the annular ramp surface.
5. The coaxial connector of claim 1, further including: an annular
ramp surface on an end face of the inner body; a retaining lip on
an inner diameter sidewall of the outer body proximate the annular
ramp surface; and a polymeric coupling body threadably coupled to
the outer body; the polymeric coupling body molded upon a spring
finger portion of injectable molded metal composition; a plurality
of spring fingers of the spring finger portion projecting towards
the annular ramp surface; wherein threading of the polymeric
coupling body into the connector body drives a distal end of the
spring fingers towards the annular ramp surface.
6. The coaxial connector of claim 1, wherein the injectable molded
metal composition is an alloy comprising zinc and aluminum.
7. A method for manufacturing a multi-shot injection molded coaxial
cable connector, comprising the steps of: injection molding an
inner body of injectable molded metal composition; positioning an
inner contact coaxial within a bore of the inner body, injection
molding a dielectric insulator between the inner body and the inner
contact, and injection molding an outer body of polymer upon an
outer diameter surface of the inner body.
8. The method of claim 7, further comprising injection molding a
slip ring comprising: a slip ring mating surface of injectable
molded metal composition; injection molding a polymer slip ring
body onto the slip ring mating surface; injection molding a
coupling body; and threadably coupling the coupling body to the
outer body, retaining the slip ring between the inner body and the
coupling body.
9. The method of claim 7, further comprising injection molding a
polymer coupling body; and threadably coupling the coupling body to
the outer body.
10. The method of claim 7, wherein the coupling body comprises a
spring finger portion injection molded of an injectable molded
metal composition; and wherein the method further comprises
injection molding a polymer about the spring finger portion.
11. The method of claim 7, further including injection molding a
coupling nut provided with a clamp ring surface; and wherein the
inner body is provided with an annular ramp surface at an end face;
the coupling nut threadable into the outer body and drives the
clamp ring surface towards the annular ramp surface.
12. The method of claim 7, wherein the injection molded metal
composition is an alloy comprising aluminum and zinc.
13. The method of claim 7, wherein the injection molding is
performed at a temperature of 1100 degrees Fahrenheit or less.
14. A method for manufacturing a multi-shot injection molded
coaxial cable connector, comprising the steps of: inserting an
inner contact into a mold; injection molding an inner body of
injectable molded metal composition; injection molding a dielectric
insulator between the inner contact and the inner body; injection
molding an outer body of polymer upon an outer diameter surface of
the inner body.
15. The method of claim 14, further comprising injection molding a
slip ring comprising: a slip ring mating surface of injectable
molded metal composition; injection molding a polymer slip ring
body onto the slip ring mating surface; injection molding a
coupling body; and threading the coupling body into the connector
body, retaining the slip ring between the coupling body and the
connector body.
16. The method of claim 14, further comprising injection molding a
polymer coupling body; and threadably coupling the coupling body to
the outer body.
17. The method of claim 16, wherein the coupling body comprises a
spring finger portion injection molded of an injectable molded
metal composition; and the method further comprises injection
molding a polymer about the spring finger portion.
18. The method of claim 14, further including injection molding a
coupling nut provided with a clamp ring surface; and the inner body
is provided with an annular ramp surface at an end face; the
coupling nut threadable into the outer body, to drive the clamp
ring surface towards the annular ramp surface.
19. The method of claim 14, wherein the injection molded metal
composition is an alloy comprising aluminum and zinc.
20. The method of claim 14, wherein the injection molding is
performed at a temperature of 1100 degrees Fahrenheit or less.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electrical connector. More particularly
the invention relates to a lightweight and cost efficient
electrical connector for coaxial cable with significant material
and manufacturing efficiencies realized by application of
multi-shot injection molding technology.
2. Description of Related Art
Connectors for coaxial cable are typically manufactured via
precision machining of a plurality of metal and dielectric elements
that are then assembled to form the connector assembly.
Machining of metal elements from metal bar stock typically results
in significant material waste and requires sophisticated high
precision machining/turning equipment and skilled operators for
same.
A previous application of polymeric materials to a coaxial
connector for use with helical corrugated solid outer conductor
coaxial cable is disclosed in U.S. Pat. No. 5,354,217, issued Oct.
11, 1994 to Gabel et al. Polymeric materials are applied to both
the connector body and a clamp nut, requiring multiple machined
internal conductive elements to form a conductive path for the
outer conductor across the connector. However, the separate metal
and polymeric elements must each be separately formed, any flashing
removed or other rework performed and each of the separate elements
assembled together by labor intensive press fit and/or hand
assembly operations to complete the connector assembly.
Manufacture, quality control, inventory and delivery coordination
to the assembly area of each of the plurality of separate elements
is a significant additional manufacturing cost. Further, a problem
resulting in a delivery delay of any one of the multiple separate
elements and or damage or loss during field assembly renders the
remainder of the connector inoperable.
In U.S. Pat. No. 5,354,217, the clamp nut threads upon helical
corrugations of the outer conductor and the leading edge of the
outer conductor is then manually precision-flared against the clamp
nut prior to connector assembly. Therefore, the connector is
incompatible with smooth or annular corrugated solid outer
conductor coaxial cable, is expensive to manufacture and time
consuming to install.
Competition within the cable and connector industry has increased
the importance of minimizing connector weight, installation time,
materials waste, overall number of discrete connector parts and
connector manufacturing/materials costs. Also, competition has
focused attention upon ease of use, electrical interconnection
quality and connector reliability.
Therefore, it is an object of the invention to provide an
electrical connector and method of manufacture that overcomes
deficiencies in such prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute
a part of this specification, illustrate embodiments of the
invention, together with a general description of the invention
given above, and the detailed description of the embodiments given
below, serve to explain the principles of the invention. Like
reference numbers in the drawing figures refer to the same feature
or element and may not be described in detail for every drawing
figure in which they appear.
FIG. 1 is a schematic cut-away side view of a first exemplary
embodiment.
FIG. 2 is a schematic isometric exploded cut-away side view of FIG.
1.
FIG. 3 is a schematic cut-away side view of a second exemplary
embodiment.
FIG. 4 is a schematic isometric exploded cut-away side view of FIG.
3.
FIG. 5 is a schematic cut-away side view of the conductive sleeve
and inner contact of FIG. 1, positioned for injection molding of
the dielectric spacer.
FIG. 6 is a schematic cut-away side view of the conductive sleeve,
inner contact and dielectric spacer of FIG. 1.
FIG. 7 is a schematic cut-away side view of the multi-shot
connector body of FIG. 1.
FIG. 8 is a schematic cut-away side view of the slip ring mating
surface of FIG. 1.
FIG. 9 is a schematic cut-away side view of the slip ring of FIG.
1.
FIG. 10 is a schematic cut-away side view of the coupling body of
FIG. 1.
FIG. 11 is a schematic cut-away side view of the coupling body of
FIG. 1, including an in situ formed sheath gasket.
FIG. 12 is a schematic cut-away side view of a third exemplary
embodiment.
FIG. 13 is a schematic isometric exploded cut-away side view of
FIG. 12.
FIG. 14 is a schematic cut-away side view of the coupling body of
FIG. 12.
FIG. 15 is a schematic cut-away side view of a fourth exemplary
embodiment.
FIG. 16 is a schematic isometric exploded cut-away side view of
FIG. 15.
FIG. 17 is a schematic cut-away side view of a spring finger
portion of the back body of FIG. 15.
FIG. 18 is a schematic cut-away side view of the back body of FIG.
15.
DETAILED DESCRIPTION
The inventor has recognized that injection moldable metal
compositions, usable with conventional polymeric injection molding
equipment, enables manufacture of multi-shot combination metal and
polymeric material connector assemblies. Thereby, numerous
manufacturing steps and the prior need for additional seals between
separate elements may be eliminated to realize a significant
materials and manufacturing cost savings.
An example of an injection moldable metal composition is
"Xyloy".TM. M950 available from Cool Poly, Inc. of Warwick, R.I.,
US. "Xyloy".TM. M950 comprises an aluminum and zinc composition
delivered in pellet form to injection molding equipment in the same
manner as raw polymer pellets. Because the melting point of zinc is
comparatively low, a combination of aluminum and zinc results in an
alloy with a low enough melting point and viscosity characteristics
suitable for use in polymeric injection molding machines without
requiring any modification thereto. Other suitable injection
moldable metal compositions preferably have melting points and
viscosity characteristics that similarly enable use of conventional
polymeric injection molding equipment with maximum operating
temperatures around 1100 degrees Fahrenheit. Injection moldable
metal compositions as described herein above do not require
specialized metal injection molding "MIM" equipment, which relies
upon application of higher temperatures and/or pressure
incompatible with traditional injection moldable polymers to
fluidize a metal alloy, such as thixotropic magnesium alloy(s).
Exemplary embodiments of coaxial connectors configured for
connection to annular corrugated solid outer conductor coaxial
cable are shown in FIGS. 1-4. FIGS. 1 and 2 demonstrate a connector
configured for the 7-16 DIN Female standard connection interface
and FIGS. 3 and 4 demonstrate a connector configured for the 7-16
DIN Male standard connection interface. One skilled in the art will
appreciate that any desired standard or proprietary connection
interface may be applied. Similarly, alternative cable attachment
mechanisms, well known in the art, for example suitable for
straight wall or helically corrugated outer conductor coaxial
cable, may be applied.
In the exemplary embodiment in FIGS. 1-4, the connector is
configured for use with annular corrugated outer conductor coaxial
cable (not shown). The cable is received through a bore 1 of a
coupling body 3, a slip ring 5 and the connector body 7. A leading
edge of the outer conductor is retained clamped between an annular
ramp surface 9 formed on an end face 10 of an inner body 17 of the
connector body 7 and a clamp spring 11, such as a canted coil
spring. The clamp spring 11 is pressed against the outer surface of
the leading edge by the slip ring 5 driven by the coupling body 3.
The slip ring 5 is rotatable independent of the coupling body 3, to
minimize the chance for damage to the clamp spring 11 during
rotation of the coupling body 3 to thread the coupling body 3 upon
the connector body 7, thus applying the clamping force to the
leading edge of the outer conductor. An inner conductor of the
coaxial cable is received into an inner contact 13 held coaxial
within the bore 1 by a dielectric insulator 15.
To minimize metal material costs and the overall weight of the
connector, a metal inner body 17 is provided as an outer conductor
conductive path between the annular ramp surface 9 and the
connection interface 19. A polymeric outer body 21 surrounds the
inner body 17 and may include, for example, tool flats 23 for use
during connector assembly and or mating threads 25 for the coupling
body 3.
The slip ring 5 spring mating surface 27 with the clamp spring 11
may be formed of metal, to avoid polymeric material creep that may
occur over time which could prevent easy separation of the clamp
spring 11 from the split ring 5 when removed, for example, for
periodic inspections of the cable and connector interconnection. A
cylindrical slip ring body 29 that maintains coaxial alignment of
the slip ring 5 with the coaxial cable may be formed from polymeric
material.
Because it is outside of the electrical path, the coupling body 3
may be formed entirely from polymeric material.
Environmental sealing of the connector may be improved by applying
environmental seal(s) 31 such as gasket(s) and/or o-rings between
the outer conductor and the connector, for example positioned
between the slip ring 5 and the coupling body 3 and/or between the
connector body 7 and the coupling body 3. A further sheath seal 33,
sealing between the coupling body 3 and an outer sheath of the
cable may be formed in place upon an outer surface of the coupling
body 3 bore 1, for example molded into an annular groove 35.
Compared to a conventional o-ring type seal inserted into an
annular groove 35, an environmental seal formed in place has a
significantly reduced chance for failure and/or assembly
omission/error, as the potential leak path between the o-ring and
the annular groove 35 and the potential for o-ring slippage out of
the annular groove 35 is eliminated.
Although the inner contact 13 may be similarly manufactured by
molding, a conventionally machined inner contact 13 is preferred to
enable use of beryllium copper and or phosphor bronze alloys with
suitable mechanical characteristics for spring finger and/or spring
basket 37 features of the inner contact 13 that receive and retain
the inner conductor of the cable and/or of the inner conductor
mating portions of the mating connector at the connection interface
19.
As used herein, multi-shot injection molding is understood to be an
injection molding manufacturing procedure wherein additional layers
are injection molded upon a base element and/or prior injection
molded layers. Preferably, the portion undergoing molding need not
be fully released from the mold. Instead, the portion is retained
aligned within the mold nest and only portions of the mold as
required to define a further cavity to be injection molded with
material are reconfigured. The resulting element is permanently
integrated without any mechanical coupling mechanisms, fasteners or
assembly requirements. By changing the injection material between
metal, dielectric polymer and structural polymers an integral
connector element is obtained that is fully assembled upon
application of the last layer.
In an exemplary method for manufacturing the connector body 7 via
multi-shot injection molding, a mold for the conductive sleeve is
injected with the injection moldable metal composition, forming the
inner body 17 conductive sleeve. An inner portion of the mold is
removed and the inner contact 13 positioned therein as shown for
example in FIG. 5. Alternatively, the inner contact 13 may be
positioned first, and mold portions nested thereupon using the
inner contact 13 as an alignment element for the various molding
operations.
A space between the inner contact 13 and the inner body 17 is then
injected with a dielectric polymer to form the dielectric insulator
15 in situ as shown in FIG. 6. The inner body 17 is also positioned
as the core for a molding step wherein a polymer is injected to
form the outer body 21 in situ as shown in FIG. 7.
The order of molding is preferably arranged based upon the melting
point of the various materials applied with the injection moldable
metal composition typically being first, the dielectric polymer
second and the outer body 21 polymer last.
The slip ring mating surface 27, as shown in FIG. 8, may be
similarly formed by injecting the injection moldable metal
composition into a slip ring mating surface mold, then, if desired,
replacing a portion of the mold to form an adjacent cavity for
injection of polymeric material to form the slip ring body 29
integral with the slip ring mating surface 27 as shown in FIG.
9.
The coupling body 3, as shown in FIG. 10, may be formed by
injecting a polymer into a coupling body mold. If desired, the
coupling body mold may be opened and portions exchanged to form a
sheath seal cavity that is then injected with a polymeric gasket
material to form the sheath seal 33 in situ, as shown in FIG.
11.
Thereby, the connector is formed in only three main elements that
are easily assembled with the desired environmental seal(s) 31,
clamp spring 11 and any further connection interface 19 portions to
form the connector.
Alternatively, the slip ring 5 may be eliminated by forming the
coupling body 3 as a monolithic polymer portion with a clamp ring
surface 39 for direct engagement with the clamp spring 11 or the
like, as shown for example in FIGS. 12-14.
As shown in FIGS. 15 and 16, additional alternative configurations
also eliminate the clamp spring 11 by forming the coupling body 3
with spring finger(s) 41. A representative coupling body and
associated connector body 7 retaining lip 43 are disclosed in
detail in U.S. patent application Ser. No. 11/672,631, "Annular
Corrugated Coaxial Cable Connector with Polymeric Spring Finger
Nut" by Jim Wlos, filed Feb. 8, 2007, co-owned with the present
application by Commscope, Inc. of North Carolina and hereby
incorporated by reference in the entirety. The resulting connector
has only two primary elements. To improve strength characteristics
of the spring finger(s) 41, a spring finger portion 45 may be first
formed from the injection moldable metal composition as shown in
FIG. 17, over which the remainder of the coupling body 3 is molded
from polymer material, as shown in FIG. 18. Environmental seal(s)
31, for example between the coupling body 3 and the cable outer
conductor and or sheath may also be added, as described herein
above.
By minimizing the use of metal, the invention provides a
significant materials cost and weight savings. By replacing metal
machining with injection molding technology, the number of separate
sub-elements is significantly reduced, manufacturing is simplified,
numerous assembly steps are eliminated and the required skill
level(s) of manufacturing personnel are each significantly reduced.
Further, because numerous prior elements are multi-shot injection
molded directly upon one another, the number of pathways between
discrete components is reduced, resulting in a connector with
superior long term sealing characteristics requiring fewer
environmental seals.
TABLE-US-00001 Table of Parts 1 bore 3 coupling body 5 slip ring 7
connector body 9 annular ramp surface 10 end face 11 clamp spring
13 inner contact 15 dielectric insulator 17 inner body 19
connection interface 21 outer body 23 tool flat 25 threads 27
spring mating surface 29 slip ring body 31 environmental seal 33
sheath seal 35 annular groove 37 spring basket 39 clamp ring
surface 41 spring finger 43 retaining lip 45 spring finger
portion
Where in the foregoing description reference has been made to
ratios, integers or components having known equivalents then such
equivalents are herein incorporated as if individually set
forth.
While the present invention has been illustrated by the description
of the embodiments thereof, and while the embodiments have been
described in considerable detail, it is not the intention of the
applicant to restrict or in any way limit the scope of the appended
claims to such detail. Additional advantages and modifications will
readily appear to those skilled in the art. Therefore, the
invention in its broader aspects is not limited to the specific
details, representative apparatus, methods, and illustrative
examples shown and described. Accordingly, departures may be made
from such details without departure from the spirit or scope of
applicant's general inventive concept. Further, it is to be
appreciated that improvements and/or modifications may be made
thereto without departing from the scope or spirit of the present
invention as defined by the following claims.
* * * * *